Screening apparatus



I p 1942- D. J. HARRllkIGTON 2,279,042

SCREENING APPARATUS Filed Aug. 3, 1940 5 Sheets-Sheet l I fivefzz orx' Jan ieZJErr April 1942- D. J. HARRINGTON 2,279,042

- SCREENING APPARATUS FiledAug. 3 1940 5 Sheets-Sheet 2 D. J. HARRINGTON SCREENING APPARATUS v April 7, 1942;

F'iied Aug. 3, 1940 5 Sheets-Sheet 3 llnn":

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' SCREENING APPARATUS Filed Aug. 3, 1940 5 Sheets-Sheet 5 fs "M g s w my u @x I Q i i fig a Mill N Eva-922 071 Patented Apr. 7, .1942

2,279,042 SCREENING APPARATUS Daniel J. Harrington,

Mani stique, Mich., assignor to Inland Lime & Stone Company, Manistique, Mich, a corporation of Michigan Application August 3, 1940, Serial-No; 350,7

5 Claims.

' My invention relates to improvements in screening apparatus, such as for examplev and more particularly, that type of apparatus in which provision is made for shaking or vibrating the portion of the apparatus upon which the material to be screened is supported.

Such apparatus as commonly provided includes a screen element or elements releasably secured to a vibrating screen body, forming a supporting structure for the screen element or elements, by fastening devices, such as for example bolts, which present a number of objections certain of which are that the fastenings often become loose (resulting in the subjecting of the; supporting structure to objectionable impact by the screen element or elements) and that oftentimes the fastenings becomelost. 1

My object is to overcome the objections presented by the means hitherto used for holding the screen element or elements in place, and provide for easily and quickly securing the screen elementor elements in place on the supporting structure and preferably easily and quickly releasing the screen element or elements from the supporting structure when desired.

I have chosen to illustrate my invention as embodied in a screening apparatus which, as to its general features of construction, is well known in the art, a description of the accompanying drawings being as follows:

Figure 1 is a view in side elevation of such a screening apparatus embodying my invention.

Figure 2 is a plan view along the line 2 on: Fig. I viewing the structure in the direction of the arrow;

Figure 3 is a fragmentary sectional view of the apparatus, the section being taken at the:

line 3 on Fig. l and viewed in the direction of the arrow. i

Figure 4 isan enlarged fragmentary sectional View, he section being taken at the line 4 on Fig; 1 and viewed in the direction, of the arrow. Figure 5 is a View in elevation of one of the the similar fluid-pressure operated devices for holding the screen elements in place.

Figure 6 is an enlarged fragmentary sectional view, .the section being taken Fig. 3' and viewed in the direction of the arrow. Figure 7 is a view in side elevation of a screening apparatus constituting another embodiment of my invention.

Figure 8' is a plan view of viewed along the line 8 on Fig. 7 inthe direction ofthearrow; 1

at the line' 6 on Cal one side portion of the apparatus of Fig. 7, the structure being ment rods.

'Figure'9 is an enlarged cross-sectional view of the apparatus of Figs. '7 and 8, the section being taken at the line 9 on Fig. 7 and viewed in the direction of the arrow.

Figure 10 is an enlarged fragmentary sectional view, the section being taken at the line I 0 on; Fig. 9 and viewed in the direction of the arrow; Figure 11, an enlarged fragmentary sectional View, the section being taken at the line H on Fig. 9 and viewed in the direction'of the arrow.

- Referring to the construction shown in Figs. 1-7, inclusive, it comprises in accordance with common practice ascreen body I2 forming a supporting'structure shown as formed of spaced apartsubstantia'lly parallel upwardly extending a side plates l3 connected together by spaced apart end cross-members M in the form of angle bars and intermediate cross members l5 'in'the form of T bars, the plates l3 "being provided along their inner surfaces with parallel cleats lBshown as in the form of angle bars which, with the bars I4 and [5, in the particular con-- struction shown, form seats for screen-elementsj hereinafter referred to; the structure described being in the" form'o'f a trough to receive the material to be screened. w

The suppo'rtir'ig structure l2v which, with its screen'elements referred to,'is vibrated in usel is spring supported on a rectangular frame l'l' supported in accordance with common practice by cables at its corners, the cables for the two corners shown being'indicated at l8, the illus-" tra.tedspring supporting means comprising pairs ofb-rackets on the plates 13 (thoseat one side of the apparatus being shown at l9), rods 20 rigidly secured at their lower ends to the frame I? and extending upwardly through openings in the brackets and on which the brackets are slidable, the upper ends of the rods '21) having heads 2 I, and springs 22 surrounding the rods and con-' fined between the brackets and stops 23'on the.

Suitable means for vibrating the supporting:

structure I2 and its screen elements referred to are provided in accordance with common practice, such means being shown'at 24and operat-- ing, when actuated, tovibrate' the structure supported on the springs 22. y

The apparatus also comprises the screen elements referred to and represented at 25, it be-' ing understood that, if desired, the desired screen' ing area may be provided by a single screen eleinstead of a plurality thereof asshown. The screen'elements showneach comprise a.

ing devices 35 for securing porting structure I2 adjacent rectangular frame 26 shown as formed of angle bars with their horizontal flanges 2'| outwardly extending and a sheet 28 of screen material extending across the opening in the frame 26 and secured to the latter in any suitable way, as for example bywelding it thereto.

The screen elements seat at the flanges 21 on the seats provided therefor on the supporting structure |2,-in the particular construction shown on the cleats l6 and the cross members l4 and I5.

In accordance with this of my invention I provide for curing of the screen elementsin place on the seats of thestructure l2 by means of power-ope erated devices. T

illustrated embodiment V the releasable se- In the particularconstruction now being de-" scribed these'power-operated devices are in the 3 ton devices 29 carried by the supporting ture l2 and which, when operated, engage-at their, pistons 30 with'the frames 260f the screen elements and clamp these frames securely against the seats. 1

The piston and cylinder-devices 29 are shown as secured at their cylinders 3.| to the plates |3 inspaced apart relation 26 being shown as engaged at each of its opposite end edges by the pistons of. two of these devices at foot plates 32 thereon, adjacent the extremi ties of these end edges.

. The cylinders 3l' of the cylinder and piston devices 29 which preferably are double-actingas represented, are shown as provided with bracket portions 33 having openings 34 to receive fastenthem to the plates l3, and ports I 36 and 31, respectively, above and below the pistons 36.

- The ports 36 and side of the apparatus are connectedwith header pipes 38 and 39, respectively, which communicate with any suitable source of'pressure medium, as for example compressed air or liquid under pressure, the flow of which'to the ends of the cylinders is controlled'by any suitable means.

Inthe construction shown the header pipes 38 and 39 at one side of the apparatus are'connected with the pressure medium supplied through a pipe-40 opening into a control valve 4| and the header pipes Hand 39 at the op osite side of the apparatus'are connected. with the pressuremedium supplied through'a-pine 42 opening [into a separate control valve. 43. though" it will be understood that all of the header pipes 38 and 39 may, if desired, connectwith a single controlling valve connected with'the source of pressure medium.

Each of the valves 4| and 43 may be' of the common 4-way type each operating when the actuating handle 44 thereof is in the position shown in Fig. 1, to supply pressure medium to the header pi e 38Iwith which the valve isc'on-,

therealong, each frame.

31 of thecylinders ateach form of fluid-pressure operated cylinder and pisstrucnected and thus to the upper ends of those of a the cylinders 3| which are in communication with this pipe and open the lower ends of these cylinders through the header pipe 39 to exhaust through the port 45 of the valve to force the screen elements 25 againstthe seats on the supthesecylinders and maintain them in this position; and when the actuatingv handle 44 is swung down, t'o connec t the lowerv ends of .these cylinders with the source of pressure medium and open the upper ends of these cylinders totheexhaust port 45, to

may be provided, if

. tending freelythrough openings 41. The plates 52 at lift the pistons 3|] in these cylinders clear of the screen elements.

Referring to the construction shown in Figs. '7 to 11, inclusive, it involves a screen body, or supporting structure, 46,'formed of spaced apart vertical side plates 41 connected together by end cross members 48 and intermediate cross membars 49 and side cleats 46:; shown as angle irons.

The supporting structure 46, which may be spring supported as in the case of the structure shown in Fig. 1, has vibrating means represented at 59 as in the case of the structure of Fig. 1.

,The supporting structure 46 also involves screening means shown in this particular construction as a single screen element 5|, but which desired, in sections.

In accordance with this embodiment of my invention-the screen element 5| is held in place on thfstructure formed of the plates 41 and cross members 48 and 49 by means which exert a pulling action on the screen element in a direction transversely thereof in .a plane parallel to that in which the cross. members 48 and ;49 are lo-i cated. I

Preferably this pulling action is exerted on opposite edges ofthe screen element in opposite directions and accordingly means so operating are'shown.

, These pulling or tautening means are shown as comprising a pair 'of plates 52 located at the inner sides of the plates 41 and pivoted at 53 be: tween their upper and lower edges at studs 54 thereon, to the outer ends of actuating members shown as piston hereinafter referred to, and ex- 55 in the plates theiriower edges have outwardly directed flanges 56 which extend into inwardly'opening channels 51 in opposite edges of the screen element 5|, these channels beingproa vided either by the channel strips, shown at 58,

secured ,to these edges of the sheet of screening material, orby bending back the screen sheet itself to form the channels. I

In the particular arrangement shown the ac-'; tuating members for the plates 52 are the'pistons 59 of cylinder and piston devices 68 and operated by any suitable pressure medium as in the case of the construction shown in the preceding figures of the drawings, v I r The cylinders of the devices 160 and represented at 6| are pivotally supported, as indicated at, at the. arms 63 of yokes 64 carried by the cylinders6|, on brackets 65 fixed on the plates 41.

The opposite ends of the cylinders -6|' communicate with a valved supply of anysuitable pressure medium as described of the construction shown inthe-preceding figures of the drawings; Thus the cylinders 6| at one side of the ap aratus connect at opposite ends with header pipes 66 and 61, respectively, andthe cylinders at the opposite side connect at opposite ends with such' header. pipes 66and 61, these sets of pipes being ,respectively, as' in the case of the header pipes I 38 and 39, or a single valve, as above suggested,

- the, control valve for one set of the header pipes 66 and 61 and of the same construction as'ithe? valves 4| and being shown at 68 and the pipe leading from the source of pressure medium to 1 the valve 68, at 69. I

I To draw the screen element 5| taut and hold it in this position the pressure medium is introduced into thecylinders 6| through the' header pipes 61 and the outer ends of the 'cylinders vented through the header pipes 66. In this operation the pistons 59 plates 52 to swing outwardly at their lower edges, fulcruming at their upper edges on the plates, and pulling outwardly on the edges of the screen element to render it taut, and applying a component of downward pressure to hold the screen in contact with its seat on frame 58a.

To release the screen element 5| for removal, the pressure medium is introduced into the outer ends of the cylinders 6 I through the header pipes at and the pressure medium at the inner ends of the cylinders vented through the header pipes 61, the plates 52 in this operation swinging in wardly to release the screen element.

While I have illustrated and described certain particular embodiments of my invention I do not wish to be understood as intending to limit it thereto as the constructions shown may be variously modified and altered and the invention embodied in other forms of structure without departing from the spirit of my invention. In this connection it may be said that While I prefer to provide for the pulling of the screen element in opposite directions at opposite edges as shown in Figs. 8-11 to secure it in position such is not necessary in carrying out my invention as one edge of the screen element may be anchored in any suitable way and all of the pulling force be exerted against its opposite edge. What I claim as new and desire to secure by Letters Patent, is: 1. In screening apparatus, the combination of a vibratable frame, screen seats carried by the frame, a screen free of connection with said 7 frame, a cylinder carried by said frame, a piston in said cylinder, a conduit for fluid pressure supply to said cylinder and means actuated by said piston to apply a component of force upon a marginal portion of said screen to press said portion against said seat during maintenance of pressure in said cylinder.

2. In a screening apparatus of the type wherein a screen carrying frame is vibrated during the screening operation, means for clamping the screen upon the frame for quick release, comprising in combination: a plurality of fluid pressure cylinders; pistons working in said cylinders each having a piston rod projecting therefrom; clamping means actuated by said rods to clamp the screen upon the frame at spaced locations along are retracted causing the 3 atleast one margin of the screen; fluid pressure supply means common to said cylinders along'at least one margin of the frame; and means to control the fluid pressure supply to simultaneously apply and release all clamping means along at least one margin of the frame. 1 'f t 3. The combination of claim.2 in, which the fluid pressure means'is connected to said cylin-" ders at both sides of the pistons andin which 7 acts to introduce fluid pressure sides of the pistons to the control means selectively to the chosen effect power actuated release as well as power acscreen simultaneously at tuated clamping of the the various locations. I 4. In a screening apparatus of the type wherein a screen carrying frame is vibrated during the screening operation, means for clamping the screenupon the frame for quick release, comprising in combination; a plurality of fluid pressure cylinders mounted at spaced locations along at least one side of the frame; pistons working in said cylinders having rods, extending into the space-above the screen; hook means engaging a margin of the screen with said rods at spaced locations; readily releasable means anchoring the opposite margin of the screen; fluid pressure supply means common to said cylinders and means to control said common supply means tosimul-.

taneously apply the tautening strain on said screen at said spaced locations.

5. In a screening apparatus of the type wherein a screen carrying frame is vibrated during the screening operation, means for clamping the screen upon the frame for quick release, come, prising in combination: seats for the screen carried by said frame; sides of the frame projecting above said seats; fluid pressure cylinders pivotally mounted exteriorly of at least one of said sides, at spaced locations therealong, on axes parallel with the plane of the screen; pistons working in said cylinders having rods projecting of the frame; plate through the adjacent side means having pulling engagement with a margin of the screen, sloping therefrom to contact with said adjacent side of the tached to said rods; and trol fluid pressure in said frame and pivotally at cylinders to exert pulling pressure on the adjacent margin of the,

screen.

' DANIEL J. HARRINGTON.

common meansto con- 

